A combined laboratory-clinical investigation is proposed to evaluate the performance of commercial low-gold, and gold substitute dental casting alloys. Nine commercial alloys of this type will be evaluated including low-gold gold base alloys, silver-palladium and nickel-chromium alloys. In addition seven experimental formulations of related composition will be studied. The laboratory study will evaluate the composition, microstructure hardness, tensile properties, heat treatability, corrosion resistance, fit and burnishability of castings of these materials. Clinical inlay castings will be prepared to evaluate intra-oral fit, burnish-ability, tarnish and corrosion, wear and marginal integrity. The research of the laboratory and clinical evaluations will be correlated to select the best (most predictive) in vitro corrosion test. Correlations will also be sought between various properties and structural characteristics of the alloys and clinical performance as a basis for selecting improved materials.